bash: apply NetBSD patches to disable importing functions from environment.

This avoids completely shellshock.

1)
 $NetBSD: patch-shell.c,v 1.1 2014/09/25 20:28:32 christos Exp $
 Add flag to disable importing of function unless explicitly enabled

2)
 $NetBSD: patch-variables.c,v 1.1 2014/09/25 20:28:32 christos Exp $
 Only read functions from environment if flag is set.